Stripping machine



Jan. 7, 1947.

L.E.SHANER STRIPPING MACHINE Filed June 22, 1944' 4 Sheets-Sheet 1 Jan. 7, 1947.

L. E. SHANER STRIPPIIIQ- MACHINE 4 Sheets-Sheet 3 FiledIJune 22, 1944 Jan. 7, 1947. l.. E. sHANER I STRIPPING MACHINE 4 Sheets-Sheet 4 Filed June 22, 1944 INI/ENTOR. Ty/ Slm/ur A #fram/Ef Patented Jan. 7, 1947 Lyle E. Shaner, Naugatuck, Conn., assignor to Box Blank Corporation, New York, N; Y., a

corporation of Delaware Application June 22, 1944, Serial No. 541,608

This invention provides a machine for the mechanical separation of scrap and blanks cut from sheets of cardboard, paperboard and similar material, hereinafter briefly referred to as board Blanks for cartons andcontainers are customarily cut in multiple from large sheets of board. The sheets are passed through a cutting and scoring machine equipped with a plurality of cutting and scoring knives. The edges of the cutting knives outline the contour of the blanks to be cut and cut through the board separating the blanks from the remainder of the sheet, the so-called scrap. The scoring knives are so adjusted as not to cut through the board, but to produce depressions therein, so-called score lines, along which the blank is later folded.

The number of blanks out from a sheet varies, depending on the size of the sheet and the size of the blank. Sheets containing nine, twelve or fteen blanksY are commonly used.

To prevent the blanks from separating in the cutting machine the cut lines are interrupted at various points so as to leave the several blanks connected with the. scrap by narrow necks or bridges having a width of approximately one thirty-secondth of an inch. The necks or bridges are left unsevered by the cutting kniveswhich at the appropriate points are provided with indentations or nicks.

After the sheets arecut and scored they are usually stacked up in well aligned stacks of considerable thickness and then stripped to separate the scrap from the blanks. The stripping is customarily done by hand by chopping away the scrap from the blanks by hand tools somewhat resembling a hatchet or a hammer.

The manual stripping entails various disadvantages. The interruption of the otherwise completely mechanized process of making a carton or container by a manual operation constitutes a rather undesirable bottleneck in the production. Manual stripping is expensive because of the requirement of skillful workers. It is wasteful because an occasional ill-directed blow with the stripping tool leads to damage to a considerable number of blanksI which have to be discarded. Thus hand stripping introduces an unpredictable loss factor into the production. Another undesirable factor is the disarrangement of the blanks which have to be re-stacked for feeding into container forming machines.

The invention provides a machine for automatically and continuously stripping blanks. A preferred form of the machine consists in substance of a movable die plate, preferably of rel- 17 claims. (c1. 164-87) ativel-y thin material such as sheet steel; The die plate contains apertures through which the blanks are forced by punches while the scrap` is being clamped to the surface of the die plate. The die plate is movable to bring its apertures into registry with the punches for a convenient removal of the scrap resting on the plate. Ac cording to one form of the invention the die plateis moved in tracks from beneath the punches onto a downwardly curved path to. shed the scrap. According to another form of the invention adie plate having therein a pluralityof sets of apertures is moved intermittently in one direction so that blanks are stripped through one setlo'f apertures while the scrap is-removed from another set of apertures of the die plate.

The objects, features and advantages of this invention will appear more fullyA from the detailed description which follows accompanied by drawings showing for the purpose of illustration preferredembodiments of the invention.

The invention also consists in certain new and original features of construction and combination of parts hereinafter set forth and claimed.

Although the novel features which are believed to becharacteristic.` of this invention will be particularly pointed out in the claims appended hereto, the invention itself, its objects and advantages andthe manner in which itmay be carried out may be better understood by refer ring to the following detailed description taken in connection with the accompanying drawings forming a part thereof, inwhich:

Fig. 1 is a side'view of. a stripping machine embodying my invention;Y l T Fig. 2v is an enlarged side view of an air valve of: the machine shown in Fi '11;

Fig. 3Y isla side'view, part yin section, of the top portion of the machine shown` in Fig. l,- a section being taken on linel 3'3 of Fig. 4;

Fig. 4 is an .elevational end view of the section of the machine shown in Fig. 3, a section being taken on line 4 4 of Fig. 3;

Fig. 5' isa fragmentary plan view of a plunger head plate;

Fig. 6 is `a fragmentaryplan view of a, cut and scored sheet` of board ready for stripping in the machine;

Fig. 7 isa fragmentary plan View of a die plate;

Fig. 8 is a fragmentary plan View of a supportingframe work for reinforcing the `die plate;

liig;A 9 is a fragmentary plan View of a top plate for the frame work shown in Fig. 8;

Fig. l0' shows in detail a pneumatically operated endstop 4forprop'erly locating the sheets of 3. board in the machine shown in Figs. l, 2 and 4; and

Fig. 11 is a simplified plan view of a stripping machine having a rotary multiple die plate.

A machine base II has four posts I2 provided with vertical guideways I3. A plunger frame I4 having laterally extending guide blocks I5 1s mounted in the gudeways I3 for vertical movement. The plungel` frame I4 is provided with four lugs I6 having pins I1 therein for connection to the lower ends of plunger rods IS. The upper ends of the plunger rods I8 are connected to cranks I5 by pins 2E), the cranks being fixedly mounted on common shafts 2I and 22.

Shaft 2I is mounted in bearings in the upper ends of two posts I2 at the receiving end of the machine and is driven by a chain 23 trained over a chain gear 24 on the end of the shaft 2|. A bevel gear 25 mounted on the shaft 2| by a pin 26 meshes with a second bevel gear 21 secured to a shaft 28 by a pin 29. The shaft 28 rests in bearings in the ends of brackets 30 at the upper ends of the posts I2, A second set of bevel gears 3| and 32 are secured to the end of the shafts 23 and 2.2 at 33 and 34, respectively, and drive the shaft 22 at the same rate as shaft'ZI, but in the opposite direction.

The plunger frame I4 is provided with a recess for insertion therein of a relatively thick and rigid plunger head plate 35, which is held in place by an end plate 31 secured by bolts 38.

The plunger head plate 35, also shown in Fig. 5, has a great number of mounting apertures 39. Bolts lll provided with washers 4I and wing nuts 42 extend through certain of these mounting apertures 39, and hold punches 43 in place. The punches 43 may be made of hardwood, and are assembled on the plunger head plate 3E in an arrangement corresponding to the arrangement of the blanks in the sheet of board to be stripped. The punches 43 have recessed holes 44 for accommodating the heads of the bolts 4D. The bolts 46 are smaller than the mounting apertures 39 in the plunger head plate 36 and preferably also smaller than the recessed holes 44 in the punches, so as to permit any number of punches to be mounted in any desired arrangement on the same head plate. v

Hold down members 45 extend through other mounting apertures 39 in the plunger head plate. Each hold down member comprises a sleeve 46 having an enlarged head 41 at one end and a screw thread at the other. A presser foot 49 is vertically slidable in the sleeve 46, and is urged downwardly by a helical spring 50 bearing with one end against the enlarged head 41 of the sleeve 43 and with the other against a flange 5I on the presser foot. Tlie downward movement of the presser foot under action of the spring 50 is lim-- ited by a pin 52 striking against the upper end of the sleeve 45. The hold down members hold the scrap in place during the stripping operation, as will later appear.

A die plate 53 of relatively thin flexible sheet steel is mounted for sliding movement in a recess 54 of a die plate supporting frame 55.

The die plate supporting frame 55 has blocks 55 engaging the` guideways I3 and guiding the frame for vertical movement. The die plate supporting frame 55 rests on four helical springs 51 mounted in pockets 58 in the base II. The upper ends of the springs are fitted in similar pockets 55 onv the underside of the die plate supporting frame 55. The spring mounting. of the die plate permits of al downward movement of the die plate whenever the force exerted on the die plate is greater than the force of the springs 51.

The die plate 53 is slidable in the die plate supporting frame in a substantially horizontal direction and may be moved, either partially or entirely, onto a downwardly curved track 6i) by a set of oscillating arms 5I. The arms 6I are pivotally mounted on the base II at 62 and carry at their upper ends pins 63 engaging elongated holes 64 in lugs 55 on a transverse bar B6 secured to the end of the die plate 53. The transverse bar 55 has a hollow channel 51 therein communieating with the atmosphere through suction ports 58. Suction may be applied at the ports 68 by withdrawing air from the channel 61 through a flexible hose 59 connected with one end to the channel by a coupling 1li and with the other end to a control valve 1I at 12.

The upward movement of the die plate supporting frame 55 under the action of the springs 51 is limited by adjustable eccentric stops 13 having handles 14 and mounted on the posts I2 at The die plate is shown in plan view in Fig. '1, and contains a plurality cf die apertures 16 arranged according to the location of the blanks in the sheet of board to be stripped. A sheet of board is shown in plan view in Fig. 6.

A die plate supporting structure is arranged underneath the punches 43, and consists of a rigid framework 11 built up from strips of flat steel mounted in an outer frame 18. The outer frame 13 rests in recesses 19 in the base. A top f' plate 83 is mounted on the framework 11' and its outer frame 18, and has in it a plurality of apertures |13 arranged to register with the apertures 16 in the die plate 53 and the punches 43.

When during the stripping operation a certain amount of force is exerted on the die plate 53, the die plate and the die plate supporting frame 55 move downwardly against the action of the springs 51 until the die plate rests on the supporting structure 1l, 18, 8U preventing flexing of the relatively thin die plate 53.

Sheets of board 3l are fed into the stripping machine'at the receiving end, a portion of the die plate supporting frame 55 being machined away at 82 to permit passage of the sheets.

The sheet 8i rests with its front edge 83 against a releasable stop mechanism 34 shown in greater detail in Fig. 10. The stop mechanism comprises a cylinder casing 85 having a piston 85 movable therein connected to a piston rod 81. A helical spring 33 bears against the piston 8G and the top wall of the cylinder casing, and urges the piston downwardly. A piston rod has at its lower end a stop 89 normally resting on the top surface of the die plate 53. The stop 89 limits the forward movement of the sheet 8! fed into the machine. The cylinder casing 85 has an extension 9G provided with an annular recess 9! into which a forked wedge S2 iits. The wedge 92 holds the cylinder casing in p-lace, and is clamped to the lower surface of the plunger head plate 36 by a set screw 93.

A flexible hose connection 34 leads from the cylinder casing 85 to a control valve 35 having a lever operating the stem 91 of a valve member. The valve member opens and closes the passage in the valve between the hose 94 leading to the cylinder casing 85 and a pipe S8 leading to a source of suction pressure, such as a pump (not shown). The valve lever 93 is operated by a cam 33 mountedon the shaft 22 to which also the crank I9 is secured. The cam 59 has an elevated portion |35 causing the valve 95 to open to admit suction to the cylinder casing 85. The remainder itl of the cam circumference is depressed and causes the valve 95 to close, disconnecting the cylinder casing B5 from the source of suction and venting the interior of the cylinder to the atmosphere to a vent port I t2 in the valve. While the interior oi the cylinder casing 85 is vented, the spring t8 forces the stop 89 downwardly until it rests against the top surface of the die plate 53. When the elevated portion of the cam $9 acts on the valve 95; air is withdrawn from the cylinder casing 85 causing the stop 33 to be raised from the die plate 53 shortly before the die plate is moved onto the curved track E@ for the removal of the scrap. Y i

Blanks removed from sheets of board `drop through the apertures in the die plate supports 11, it and 8! and accumulate on a receiving platn l form 253 vertically movable by means of chains |54 trained over sprocket spools |05 on a shaft ist. The shaft |55 is mounted in bearings |51 in the base |I, and carries at one end a worm gear |03 meshing with a worm |39 on a transverse shaft Ile. The transverse shaft is mounted in bearings III and carries a ratchet gear ||2 secured by a pin i3 and an oscillating lever ||4 held in place by a collar I I5 secured by a pin 6. The oscillating lever lle carries a pawl Il? engaging the teeth oi the ratchet gear I I2. The oscillating lever let is operated by a rod ||8 linked to an oscillating arm H9 at |263. The 0scillating arm II 9 is pivcted at |2| on the base and is operated by a further rod |22 connected to a triple armed lever |23 at |24. The triple armed lever |23 is pivoted on a bracket |25 at 526, and is operated by a rod |21 leading to the end of a single armed lever I 28 pivoted to the base EI at |25. The single aarmed lever |28 carries a pin |36 engaging the internal cam race |3| of a cam member |32 mounted on a shaft |33. Cam 32 and shaft |33 are driven by a chain gear i3d around which a chain |35 is trained leading to a similar chain gear |35 on the shaft 2|.

When the shaft 2| isA rotated the cam member |32 is driven by the chain |35 at the same rate as the shaft 2| causing the lever |28 to oscillate. The oscillating movement of the lever |28 is transmitted to the triple armed lever |23 through the` rod |21, and thence through rod |22, arm I9 and rod I8 to the pawl and ratchet H2, Il'l for lowering theplatform |63 by the thickness of one blank `for each revolution of the cam |32.

The triple armed lever |23 further operates a feed conveyor |31 by a push rod |38 linked to thetriple armed lever |23 at |39. The conveyor B31 is slidable in horizontal tracks |48, and comprises a plurality of parallel belts |4| trained over pulleys on shafts |42 and |53. The assembly of conveyor belts |4| is connected to a vertically extending lug |44 to which the push rod |38V is hingedly connected. Y

The feed conveyor |31 normally forms part of an automatic cutting and scoring machine or an automatic printing, cutting and scoring machine to which the stripping machine may be attached as a terminal unit. Such automatic machines are well known in the industry, and a detailed description of their function and structure is not required for an understanding of this invention. Sufhce it to say, that printed, cut :and

Ascored sheets of boards are deposited on the `conveyor mechanism |31, which .is .thenzmoved underneath the elevated plunger heads I4, 36 carrying the punches 43, while the pulleys on the shaft |42 and |43 of the conveyor are at rest. The conveyor belt assembly I4| is then withdrawn from underneath the plunger of the strippngmachine while simultaneously the conveyor belts are driven in clockwise direction causing the sheet on the conveyor to be thrown off and placed on the die plate 53 with the front edge 83 of the sheet 8| resting against the stop 89. After the conveyor assembly |4| has reached its retracted position shown in Fig. 1, the conveyor belts |4| come to rest and a new sheet of board is deposited thereon.

The flexible die plate 53 is horizontally movable into and out of registry with the plungers 43 bythe oscillating arms 6|, one arm being preferably mounted on either side of the machine. The oscillating arms 6| are pivotally mounted to' the base at 52, and carry a pin |45 engaging the internal race |48 of a cam member |41, there being preferably one cam for each lever 6|. The cam members |41 are mounted on a common shaft |48 carrying a chain gear |49 driven by a chain |50 from a second ,chain gear |5| on the shaft 22.

As the levers 6| are swung'clockwisely into the end position indicated in dash dot lines at G I the die plate 53 and the scrap resting thereon is moved onto the curve track 60, causing the scrapjto be shed off the die plate 53.

The scrap is retained on the die plate 53 during its movement by suction applied at the ports 63 at the end of the die plate. The valve 1| controlling the application and the release of Y section at the ports is operated by the oscillat inglever BI through a linkage |52 pivotedly connected to the lever 6| at |53, and to a control arm |54 on the valve at |55.

A suction duct |56 leading to suitable source of suction, such as a pump (not shown), is conneoted to the valve at |51. vThe valve is proved with a vent port |53 leading to the atmosphere and with a hose connection 12 for the suction hose 69 leading to the suction ports 68 in the die plate.

In the position shown in Fig. 1, suction is applied at the ports 68 firmly retaining the sheet or scrap on the die plate. The suction is maintained while the die plate is being moved from underneath the punches and relieved as the oscillating levers approach the end position 6|. In this position the suction ports G8 are disconnected from the source of suction and admit atmospheric air through the vent port |58.

A supplementary tray plate |59 for blanks rests normally on rollers |60 to one side of the stripping machine as shown in Fig. l. It is guided in tracks ISI in the base and may be moved into a position between the punches 43 and die plate `53 by a handwheel |62 provided with a handle |63. The handwheel is mounted on a shaft |64 and operates a friction roller |65 engaging the plate |59. In the position below the punches 43 the tray plate |59 is supported by rollers |56 mounted on brackets |61 and serves as a temporary receiving platform for blanks which are being separated from the sheet, permitting removal o'f lthe stacks of blanks |58 from the regular vreceiving platform |03 without interruption of the operation of the machine.

The layout of the blanks in a sheet of board is shown in Fig. 6. The blanks |68 are cut along lines |59, the cut lines being interrupted by nar- :row :necks or Ybridges l|10 which lmaintain the 7 blanks in connection with the surplus material or scrap |1| surrounding the blanks. The blanks |68 are further scored along score lines |12 along which the blanks are later folded to form cartons.

During the stripping operation the narrow` necks or bridges |10 are severed to separate the individual blanks from the scrap. The stripped scrap remaining on the die plate 53 forms an open net work orl mesh.

The die plate 53 on which the sheet 8| rests during the stripping operation contains die apertures 16 arranged in the same pattern which the blanks |68 assume in the sheet of board 8|. The configuration of the apertures is similar to that of the cut lines defining the outer edges of the blank. However, I prefer to make the apertures in the die plate slightly narrower in width, or length, or both width and length, so as to cause the blank to be slightly fiexed or deformed while the blank is forced through the respective die plate aper ture 16. I nd that this flexing of the blank greatly facilitates the severance of the necks or bridges which connect the blanks |68 with the remainder of the sheet 8|.

Whether only the length or the width of the die plate aperture, or whether both dimensions should be made shorter than the corresponding dimension of the blank depends on the particular form of the blank. In the illustrated form of blank, which is the blank for a cigarette carton, I prefer to make the length a, as well as the width b, slightly shorter than the corresponding dimensions of the blanks |68.

The supporting top plate 80 has apertures |13 therein, which are larger than the blanks |68 so `as to permit the blanks to drop through the aper- :tures |13 freely.

The apertures 16 in the die plate 53, and the .apertures |13 in the support plate 80, may be :machined sim ltaneously.

This is preferably ,done by superimposing two sheets of steel, one for the die plate 53, and one for the support plate B6, and machining apertures of the outline of the die plate apertures 16 into the two superimposed plates. Thereafter the plates are separated and the apertures in the support top plate 80 enlarged, until the desired size and form of the apertures |13 is reached. The configuration of the apertures |13 need be less detailed than that of the die plate apertures 16, as is also shown in the drawings. The procedure of machining plates 53 and 80 together insures a proper registry of the respective apertures.

The framework 11 in the frame 18 reinforcing the top plate 86 is so laid out as to support the relatively thin top plate 80 at all vital points.

The top plate 80 may be omitted and the reinforcing structure consisting of the framework 11 and the outer framer18 be used as the immediate support for the die plate. However, I find it prefa erable to build up a reinforcing supporting structure for the die plate 53 out of a framework 11 and frame 18, and a top plate 80 since the surface of the sheet metal top plate 80 is smooth and requires no machining and permits of the use of a supporting framework of great tolerances and consequent inexpensive construction, whereas a framework of more detailed layout would be required properly machined to the necessary surface smoothness, if the top plate 80 were omitted.

The fitting of the machine for a new type of sheet andblank may be carried out in the following manner:

The plunger head plate 38 is removed from the machine and placed bottom side up. The corre-1 spending die plate 53 is placed upon it, also with its bottom side up. The punches 43 are then placed upside down into the spaces defined by the die plate apertures 16, adjusted so as to leave ample clearance between the outer edges of the punches and the edges of the die plate apertures 16, and then secured to the plunger head plate 36 by means of the bolts 40, washers 4| and winglv nuts 42. After the punches are in place, the die plate 53 is removed from the surface of the plunger head plate 36 and the hold-down elements 45 are secured between the punches so as to engage the scrap portions of the sheet to be stripped. After the punches 43 and the hold-down elements 45 are assembled with the plunger head plate 36, the head plate is slid into the plunger frame I4 and secured therein by the end plate 31 and bolts 38. Thereafter, the rigid support 11, 18 for the die plate is placed in the machine and finally the die plate 53 slid into its guideways or recesses 54 in the die plate supporting frame 55, whereafter the machine is ready for a final check and operation.

The operation of the machine is as follows:

While the cranks I9 of the machine and the plunger I4, 36 and punches 43 are near their uppermost position, the feed conveyor |31 carries a sheet 8| into the space between the die plate 53 and the plunger assembly 43, 35, and deposits it on the die plate 53 while the conveyor |31 recedes. The front edge of the blank 8| rests against the stop 89 of the pneumatically operated stop mechanism, which during this phase of the operation is in its lowermost position.

As the cranks I9 continue to revolve, the left hand crank in Fig. 3 rotating clockwise, and the right hand crank, rotating counterclockwise, the plunger approaches the sheet 8| on the die plate 53. The hold-down elements 45 on the plunger make contact with the sheet first and clamp its scrap portions firmly against the die plate 53. Shortly thereafter the punches 43 make contact with the blank portion |13 of the sheet. The force exerted on the die plate 53 causes the die plate 53 and its supporting frame 55 to move downwardly against the action of the helical springs 51 until the die plate 53 comes to rest on the top plate 88 of the rigid support 11, 18.

The punches then force the blanks through the die plate apertures 16 separating the blanks |68 from the scrap portions of the sheet 8l which remains firmly clamped to the top surface of the die plate 53. The blanks |68 drop through the apertures of the die plate supporting structure 11, 18, 80, and form stacks of blanks on the receiving platform |03. As herein before described, the receiving platform |03 moves downwardly by an amount equal to the thickness of one blank during each revolution of the crank I9, so as to maintain the top level of the stack of blanks |68 at a constant distance from the die plate support 18 and 8i).

As the cranks I0 continue their revolutions, the punches 43 are withdrawn from the die plate apertures 16, and the die plate returns to its uppermost position under action of the springs 51 until the guideways 54 in the die plate supporting frame 55 registers with the corresponding guideways in the curved tracks 60. The uppermost position of the die plate supporting frame 55 is adjustable by means of the eccentric stops '13 on the posts l2. In the elevated position there 4is ample clearance between the die plate 53 and the supporting structures 11, 18, preventing the die plate in theevent of accidental deformation or bending of relatively narrow projections from engaging the supporting structure during the following withdrawal from beneath the punch assembly.

The cam member MilV moves the oscillating arms Si clock'avisely moving the die plate 53 from underneath the punches for disposal of the scrap resting thereon. During the withdrawal of the die plate 53 from underneath the punches 43, the scrap is held on the die plate by suction exerted at the suction ports 68.

As the die plate 53 approaches its outermost position, the control valves controlling the suction is moved to a position in which the suction ports are disconnected from the suction conduit l?, and vented to the atmosphere through the vent port E58.

The release of the suction, the inertia of the moving scrap and gravity cause the scrap to slide off the curved die plate 53, which thereafter is returned by the levers bi moving in counter-clockwise direction to a position of registry of the die plate apertures 'it with the punches. During the return movement of the die plate 53, suction is restored at the ports tit, causing the new sheet about to be deposited to adhere firmly to the die plate 53. A

As the cranks i9 approach the uppermost posithe feed conveyor' Uil is again advanced into the space between the elevated plunger assembly and the die plate and the cycle of operation is repeated.v

After a sufficient number of blanks has accumulated on the receiving platform ldlthe auxiliary tray 15s is moved underneath the die plate support it, by turning the handwheel H62. In this position the auxiliary tray receives the blanks it@ and permits removal of the stacks of blanks from the receiving platform without interruption oi the continuous operation of the machine.

A form of machine in which the die plate is moved intermittently in one the same direcis slL .n in plan viewin Fig. ll.

A cra k-driven power press a base llt upon wl is mounted a substantially vertical standard 5 supporting a table Eid and a head structure Vl carrying .the two bearings lil and lll@ for a crankshaft its. The crankshaft has a hywheel it! connected to one end and carries a crank portion at the other engaging the `top bearing E82 of a substantially vertical plunger rod. The plunger rod moves a plunger |83 mounted between guideways |85 and face plates ,E secured to the head structure by bolts H36.

A plunger frame-itl is carried by the "lower end of the plunger M3 and vhas secured to its underside a plunger headplate and punches similar to the headplate and punches shown in Figs. 1, 3 and 4, the headplate being held in place by an end plate |88 secured by bolts |85?.

A rotary die plate It@ is mounted underneath the plungerand punchassembly and is rotatable about a center post lill.` The rotary die plate contains two sets of die apertures |92, one being in registry with the punches on the plunger `assembly and therefore not visible in the drawcally moved up and down by theA cra-nk on the crankshaft ist driven by a belt trained around the flywheel [8| and a pulley |96 on a motor |91. Suitable mechanism, also driven by the motor and not shown in the drawings, turns the rotary die plate |90 one-half revolution about thepost It!! after each down-and-up-stroke of the plunger |83 whereafter the 'arresting mechanisrn ldd arrests the die plate, in `the proper position with respect to the punches.

A feed conveyor |31 havingindividual belts |4| trained around pulleys on a front shaft |43 feeds scored and cut sheets of board into the space between the raised punches and the die plate |53!! to deposit them over the respective set of die apertures |92. The blanks are then removed from the sheet in the same manner as described Ln connection with the operation of the machine shown in Figs. 1, 3 and 4. After the punches have cleared the die apertures |92 the die plate |953 is rotated at about the center post 9| carrying the scrap with it for removal by a conveyor belt |98 the lower run of which frictionally engages the upper surface of the die plate |99 Aand sweeps the scrap 01T.

A particular feature of this invention is that the novel stripping machine may be added as a separate unit to printing, scoring and cutting machines of conventional construction and may be so timed as to operate in synchronism therewith. Thus the production of a carton blank becomes a continuous mechanized process uninterrupted by any manual operations as were heretofore required for the separation of blanks from scrap. This isa particular feature of my invention contributing to a material reduction of the cost of the blanks in connection with the further feature of elimination of spoilage of blanks which is unavoidable where` the manual method of stripping is used. l

Obviously the present invention is not restricted to the specific forms of the machines herein shown and described. Various changes of design and construction may be made. Features may be added or omitted and substitutions of similar and equivalent mechanical elements may bemade for the ones shown. Such changes and modifications will be obvious to persons skilled in the `art and manifestly do not involve a departure' from the spirit and teaching of this invention.

What is claimed is:

1. A machine for removing from blanks preycut from a sheet of cardboard, paperboard, and

the like,l scrap adhering to said blanks, comprising, a movable die Aplate for receiving sheets of board, said die plate having apertures therein; means for forcing the blanks through said apertures; means for engaging said scrap while the blanks are being forced through the die plate apertures;` and means for moving said die plate from oney position in which blanks are forced through its apertures to a different position forthe removal of the scrap therefrom.

2. A machine for removing from blanks precut from a sheet of cardboard, paperboard,` and the like, scrap adhering to said blanks, comprising,.a reciprocating plunger head; a plurality ofv punches mounted on said' plunger head foren` gaging' said blanksi'hol'd down means for engag=' ing saidscrappavmovable die plate having apertures thereiniand meansfor moving saidV die plate into and out of registry with said punches for removal of scrap from said die plate.

.. .3. Al machine for removing; lfrom blanks pre-i cut froma sheet of cardboard, paperboard, and

the like, scrap adhering to -said blanks comprising, a reciprocating plunger head; a plurality of punches mounted on said plunger head for engaging said blanks; hold-down means for engaging said scrap; a die plate support underneath said plunger head; a movable die plate overlying said support; and means for moving said die plate out of registry with said punches for removal of the scrap from said die plate.

4. A machine for removing from blanks precut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks comprising a reciprocating plunger head; a plurality oi punches mounted on said plunger head for engaging said blanks; a plurality of hold-down elements for engaging said scrap; a die plate support underneath said plunger head; a curved track; a flexible die plate overlying said support; and means for moving said die plate from underneath said plunger onto saidcurved track for shedding the scrap oft' said die plate.

5. A machine for removing from blanks precut from a sheet of cardboard, paperboard and the like, scrap adhering to said blanks, comprising a reciprocating plunger head; a'. set of punches mounted on said head for engaging the blanks of a sheet; hold-down means for engaging the scrap of the sheet; a die support underneath said plunger head, said support having apertures permitting the blanks to drop therethrough; va die member having therein a plurality of sets of die apertures, each set corersponding to said set of punches; said die member overlying said support; and means for moving said die member relatively to said support for bringing'said die apertures successively into registry with said punches.

6. A machine for removing from blanks precut from a, sheet of cardboard, paperboard and the like, scrap adhering to said blanks, comprising a reciprocating plunger head; a set of punches mounted onsaid head for engaging the blanks of a sheet; a set of hold-down elements for engaging the scrap of the sheet; a die support underneath said plunger head, said support having apertures Ypermitting the blanks to drop therethrough; a rotatable disk having therein aA plurality of sets of die apertures, each set corresponding to a set'of punches, said disk overlying said support;A and means for rotating said disk for bringing said sets of die apertures successively into registry with said punches'.

7. A machine for removing fromblanks, precut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising adie plate support; a movable relatively thin die plate having apertures therein, the die plate being adapted to receive pre-cut sheets of board; means for forcing the blanks through said apertures and moving said die plate into engagement With said support While blanks are being forced through said die plate apertures; and means for moving said die plate from one position in which blanks are forced through its apertures into a different position for the removal of scrap therefrom.

8. A machine for removing from blanks precut from a sheet of cardboard, paperboard, and the like scrap adhering to said blanks comprising a reciprocating plunger head; a plurality of punches mounted on said plunger' head for-en"- gaging said blanks; hold-down means for engaging said scrap; a die plate support underneath said plunger head; a relatively thin die plate overlying said support, the die plate`v being deformable under the action of the punches on the 12 sheet Without support and having die apertures therein corresponding with said punches; and means for moving said die plate into a rst position of registry of its apertures with said punches for a punching operation and into a second position for removal of scrap resting on said plate.

9. A machine for removing from blanks precut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising a reciprocating plunger head; a plurality of punches mounted on said plunger head for engaging said blanks; a plurality of hold-down elements mounted on said plunger head for engaging said scrap; a relatively thin die plate movably mounted underneath said plunger head, the die plate having die apertures corresponding to said punches; a iixed die plate support beneath said plunger head for supporting said die plate against deformation during the punching operation, said support having apertures therein corresponding in location substantially to theV apertures in said die plate and permitting blanks to drop therethrough; and means for moving said die plate relatively to said support into a first position of registry of its apertures with said punches and into a second position for removal of scrap from said plate.

10. A machine for removing from blanks precut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising, a punch for engaging a blank, the punch being smaller than the blank; a die plate having an aperture smaller than said blank, but larger than said punch; hold-down means for engaging said scrap; and means for moving said punch and said die plate relatively to each other for forcing said blank through said aperture.

11. A stripping machine for removing from blanks pre-cut from a sheet of cardboard, paperboard, and the like scrap adhering to said blanks, comprising, a plurality of punches for engaging said blanks, the punches being smaller than the blanks; a die plate having die apertures smaller than said blanks but larger than said punches; hold-down means for forcing said scrap against said die plate; and means for moving said punches to force said blanks through the apertures in said die plate.

12. A stripping machine for removing from blanks scrap pre-cut from a sheet of cardboard, paperboard, and the like-scrap adhering to said blank, comprising, a plurality of punches for engaging said blanks, the punches being smaller than the blanks; a movable die plate having die apertures smaller than said blanks but larger than said punches; hold-down means for forcing said scrap against said die plate; means for moving said die plate into and out of registry with said punches; and means for moving said punches to force blanks through said apertures.

13. A stripping machine for removing from blanks pre-cut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blank, comprising, a plunger head; means for mounting said plunger head for reciprocating movement; a plurality of punches adjustably mounted on said plunger head, the punches being smaller than the blanks; a plurality of hold-down members adjustably mounted on said plunger head; a'relatively thin die plate having die apertures therein smaller than said blanks but larger than said punches unless supported; means for mounting said die plate for movement into and out of registry with said punches; a rigid base; a

13 relatively thin top plate secured to said base, said base and top plate having apertures in fixed registry With said punches, the to-p plate being adapted to engage the underside of said movable die plate.

14. A stripping machine for removing from blanks pre-cut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising, a plurality of punches; means for mounting said punches for reciprocating movement; a relatively thin die plate having die apertures therein, said die plate being de formable under action of said punches unless supported; means for mounting said die plate for movement into, and out of, registry with said punches, a rigid support adapted to engage the underside of said die plate; and yielding means for supporting said die plate normally out of engagement with said support and permitting said die plate to rest against said support when acted upon by said punches.

15. A stripping machine for removing from blanks pre-cut sheets of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising, a plurality of punches; means for mounting said punches for reciprocating movement; a relatively thin die plate having die apertures therein, said die plate being deformable under action of said punches unless supported; a curved track for said die plate; means for mounting said die plate for movement into registry with said punches for stripping and out of registry with said punches onto said track for removal of scrap; a rigid support adapted to engage the underside of said die plate; and yielding means for supporting said die plate normally out of engagement with said support and permitting said die plate to rest against said support when acted upon by said punches.

16. A machine for removing from blanks precut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising, a plunger head; means for mounting said plunger head for reciprocating movement; a set of punches mounted on said plunger head for engaging the blanks of a sheet, said punches being smaller than said blanks; hold-down means cn said plunger head for engaging the scrap o-f the sheet; a die'support underneath said plunger head; a die member having therein a plurality of sets of die apertures, each set corresponding to' said set of punches, said die member overlying said support, said die apertures being larger than said punches but smaller than said blanks; and means for moving said die member relatively to said support for bringing said die apertures successively into registry with said punches.

17. A machine for removing from blanks precut from a sheet of cardboard, paperboard, and the like, scrap adhering to said blanks, comprising, a plunger head; means for mounting said plunger head for reciprocating movement; a set or punches mounted on said plunger head for engaging the blanks of a sheet, said punches being smaller than said blanks; a set of hold-down elements mounted on said plunger head for engaging the scrap of the sheet; a die support underneath said plunger head; a disk having therein a plurality of sets of die apertures, each set corresponding to said set of punches, said disk overlying said support, said die apertures being larger than said punches and smaller than said blanks; and means for rotating said disk for bringing said die apertures successively into registry with said punches.

LYLE E. SHAN ER. 

